//
// Created by Administrator on 2025/4/16/周三.
//
#include "iostream"

using namespace std;
// 在全局区开辟常量PI
const double PI = 3.14;

class Circle {
public://设置公开权限
    int m_r;//半径

//    行为
    double calculateZC() {
        return 2 * PI * m_r;
    }
};

int main() {
    Circle c;
    c.m_r = 10;
    cout << "ZC = " << c.calculateZC() << endl;
    return 0;

}